Comparison of the in vitro translation products of mRNA isolated from suspension cultures of Phaseolus vulgaris grown on maintenance and induction medium.

1. Bean cells grown in suspension culture on maintenance medium have been shown to differentiate (xylem and phloem production) when they are transferred to an induction medium containing an increased ratio of naphthylacetic acid to kinetin.-2. Conditions for the extraction and isolation of undegraded mRNA are described. The mRNA has been translated by 2 in vitro protein synthesizing systems; the wheat germ and the mRNA-dependent-reticulocyte-lysate preparations.-3. A greater proportion of the mRNA from cells on maintenance medium coded for high molecular weight products compared with that from cells on induction medium.-4. mRNA from cells on induction medium coded for a relatively large amount of a few polypeptides whereas that from cells on maintenance medium coded for a large number of polypeptides all present in fairly equal amounts.